Install libasound2-plugin-smixer by entering the following commands in the terminal:
sudo apt update sudo apt install libasound2-plugin-smixer
Description:
smixer plugin for ALSA library
This package contains the smixer (Simple Mixer) interface for the ALSA library. . ALSA is the Advanced Linux Sound Architecture.
Homepage: https://www.alsa-project.org/
Version: 1.1.3-5
Section: universe/libs